1. Field of the Invention
The present invention relates to a cooling system for an electronic circuit device. More particularly, it relates to a printed circuit board holding electronic circuit components, wherein these components are cooled by a cooling system that includes a cooling module or a series of cooling modules for removing the heat dissipated from the components and transferring it to a coolant flowing in a passage.
2. Description of the Related Art
In conventional cooling modules for an electronic circuit device a heat transfer element, such as a heat transfer plate or a heat transfer piston, is placed in direct contact with the circuit components, such as integrated circuits (IC), large scale integrated circuits (LSI), and semiconductors, by pressure from a spring or a bellows, to remove the heat dissipated from these circuit components. The heat transfer elements are directly or indirectly exposed to a coolant (usually a gaseous coolant), in such a manner that the heat removed from the circuit components is transferred to the coolant by means of the corresponding heat transfer element. However, these prior arts have the following drawbacks: (a) the surface area for an effective heat transfer between the heat transfer elements and the corresponding circuit components is relatively small; (b) complete surface contact therebetween cannot be achieved, resulting in a large and non-uniform thermal contact resistance; and (c) any change in the pressure from the spring or bellows leads directly to a change in the thermal contact resistance, resulting in an unstable thermal contact resistance. All of the above are the causes of a large loss in the heat transfer efficiency. Additional methods of cooling electronic circuit devices can be found in a related case filed on Jan. 22, 1985 and having Ser. No. 693,432.